schellenger



July 3, 1928-.I l

, N. C. SCHELLENGER JACK Filed Dec. 30, 1925 Was/@RMK Patented July 3, 1928.

NEWTON C. SCHELLENGER, OF ELKI-IART, INDIANA.

JACK.

Application led December 30, 1925. Serial No. 78,284.

The present invention relates to a novel .form of jack for plugs oit the telephone type.

One particular advantage of my type of jack over the jacks now on the market, is that it is much shorter and. consequently, takes up .less room. This adif'antage will readily be appreciated when it is known that considerable difficulty is encountered when building a radio receiver. in trying to get the jacks out ot the way ot theother instruments in the set. Hence, receivers must oftentimes be made larger in order to accommodate the jacks. Likewise, the amateur set builder finds, when he tries to assemble his parts,

' that the jacks are in the way because of their length. My jack ohviates the above ditliculties, because it is only about onehalf as long as the ordinary type ot jack.

`Another feature ot my invention is the ready accessibility and wide spacingl of the lugs on the jack to which connections-are to be made. It is well known that considerable difficulty is often experienced in getting the leads soldered to the lugs of the jack springs because of the tact that these lugs in the ordinary type ot jack are hunched closely together. In my jack the separa-tc contacts and lugs are spread and widely separated from cach other so` that leads may be run and solderedv thereto with very little difficulty. This not only makes the job of sol.- dering comparatively easy, but also ap preciably reduces the amount oit' labor required.

Another feature of my invention :is the provision of novel forms ot' jack springs which are adapted to contact with the plugs inserted into the ack. In order to obtain the necessary amount of spring tension, I bend the spring back on itselt. Hence, I am able to get a spring which is as effective as the ordinary type of straight spring used in jacks now on the market in about one-half the length. Also. instead ot having the lugs to which the leads are to be soldered, extending in the general longitudinal direction of the spring, I have them extending out laterally, or at substantially right angles to the spring itself. This, again. cuts down on the amount of space required by the jack in the longi tudinal direction.

Still another feature of the invention lies in the fact that the jack springmay be adjusted so as to make proper contact with the plug which is adapted. to cooperate with the jack after the jack has been assembled. In

my jack this may be done without loosening the screw which secures the jack Spring to the traine. Also,` the effort required to pull the plug out ot engagement with its cooperating springs is considerably greater than that required to insert the plug into the jack. This is because the springs are so formed that any pull on the plug, when an attempt is made to withdraw it, causes thel springs to tighten their grip thereon. The advantage ot this is that the plug cannot readily be pulled out of the jack by any accidental pulls on the cord to which the plug is connected.

The invention also has certain other fea tures. such as sin'iplicity and rigidity of construction. For example, it will he noted that i the springs are so secured to the frame of the yiack as to prevent any lateral motion thereof. The parts are all relatively simple and may be easily stampedv out on a punch press, thereby reducing the manufacturing cost of the jack to a minimum.

Another feature resides in the ease with which proper tension of the springs may be secured without causing` the spring to get into the way of the plug.

Now, in order to acquaint those skilled in the `art with the manner ot constructing a j ack of my invention, l shall describe in connection with the accompanying drawings,

one embodiment in which the invention may i appear.

In the drawings Fig. 1 is a rear elevational view of the jack mounted ona panel;

Fig. 2 is a top plan view ot same; Fig. 3 is a longitudinal sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a top plan view ot' another modification; i

Fig 5V is a side elevational view ot same; Fig. 6 shows the manner in which the ack springs may be adjusted for making proper contact with the plug;

Fig. 7 shows the action of the springin resisting withdrawal oil plug;

FigS is a partial view inv plan ot the mounting portion ot' the jack springs; and

Fig. 9 is a partial view in elevation of same.

The jack in its preferred term comprises a l`generally U-shaped frame 5 which has a substantially flat hase portion 6 and a pair ot laterally extending leg-s 7 and 8 which are made integral therewith and preferably at rightangles thereto. Each of the legs 7 and 8 have the general shape of a Y. At their mounted ends they are provided with the openings 9 and 10, respectively. These openings extend partly into the base 6 and permit the ack springs, which are hereinafter described, to extend therethrough.

The novel form of jack springs which I employ are shown in F ig. 3 and are designated by the numerals 11 and 12. The jack spring 11 comprises a. long leg which has a hump portion for contacting purposes, and a short leg, which is formed by bending the spring back on itself. The short leg extends through the opening 9 of the frame and is secured to the leg 7 thereof by means of a screw 13 which is adapted to pass through an opening in the spring. It will be noted that this opening is countersunk .and that the portion just below the head of the screw 13 is generally conical in form. Furthermore, the insulating washer 15 which separates the screw from the jack spring has also a depressed portion which is adapted to seat on the countersunk opening of the spring. When the screw 13 is threaded into Vthe frame 5, the conical portion adjacent its head will force itself into the depressed portion of the insulating'washer 15. In this way, I am able `to do away with the necessity of having a 30` bushing between the screw and the opening in the short leg portion of the jack spring 11. This renders the assembly of the springs on the jack comparatively simple. A strip of insulation 16 between the short leg of the jack spring 11 and the frame 5 insulates them from each other. It will also be noted that the opening 9 is large enough to permit an adjacent portion of the jack spring to freely clear the frame 5. I also provide a lug member 17 which is integral with and extends out laterally from the short leg of the spring 11. As stated heretofore, this arrangement requires less space and also permits the leads thereto to be soldered thereon with greater ease.

The jack spring 12 is of much the same general construction as the jack spring 11, except that it has its hump contact portion a little further from the mounting. This is necessary because this spring is adapted to contact with the tip of a plug inserted into the `iack'and the spring 11 is adapted to contact with the sleeve portion of the plug. Each of the springs 11 and 12 might also be described as having a long leg and a short leg converging at a U-shaped fulcrum; the short leg being secured'to the jack frame and the long leg being adapted to make contact withthe plug. The short leg of the spring 12 likewise extends through an opening 10 in the frame and is secured to the leg 8 thereof in much the same manner. In this instance,'a screw 18 is provided which extends through an opening in the short leg of the spring. This screw also has a conical portion adjacent its head which tits into a depressed portion in the insulating washer 19. A strip of insulation 20 insulates the spring from the leg 8 of the frame. A lug 22 is formed integral with the short leg of the spring and also extends out laterally therefrom.

To prevent any lateral movement of the jack springs 11 and 12, I provide a series of teeth l() along the periphery of the under sides of the mounting portions. thereof as shown in Figures 8 and 9. These teeth are adapted to bite into the insulation strips 16 and 20, respectively, and in so doing keep the springs from turning. Also, if desired, .each of the jack springs may have secured to their respective contact portions, the contact points 41.

Substantially adjacent the free end of the legs 7 and 8 of the frame 5, are the cont-act members 21 and 23. Each of these members has the general shape of an l. and comprises a mounting portion and a laterally extending contact portion, each of which may be provided with the contact points ft2. These Contact members are secured to the frame 5 in much the same manner as the jack springs 11 and l2. The contact member 21 has an opening in its mounting portion which is countersunk to receive the screw2/l. This screw is provided with a conical portion be low its head which seats in a depressed portion in the insulating washer 25 which, in turn, seats in the counter-sunk portion provided in the screw opening. The` contact member and the frame are further separated from each other by the insulating strip 16 which lies betwen them. Likewise, the oontact member 23 is secured to the leg 8 by a screw 27 which extends through an opening in the mounting portion thereof. The screw and the frame are insulated from the contact member 23 by means of the insulating washer 28 and the insulating strip 20. In this instance also, the screw 27 and insulating washer 28, are similar to the screw 24 and the washer 25.

The lower or base portion v6 of the frame 5 is provided with a central opening Vwhichris threaded to receive a sleeve 30. By means of-this sleeve, the jack may be secured to a panel 31, as illustrated in Figs. 1 and 2. IVashers 32 and 33 serve to space the head of the sleeve 30 from the panel 31 to permit the tip and sleeve portions of a plug 34 to properly contact with the jack springs 11 and 12, respectively. I

In operating the device, it will be noted that when the plug 311 is inserted in the jack, the contact points 41 on the ack springs 11 and 12 will be forced 'out of contact with their cooperating contact points 42 on' the contact members 21 and 23. vWhen this is done, the circuit will be completed' through the plug 34. As soon as the plug is removed,

llo

the jack springs 11 and 12 will again resume normal contact relationship with the Contact members 21 and 23, which normally serve as stops to hold the springs under` tension. These stops permit much heavier tension to be put upon the springs.

While I provide a pair of lugs 35 and 36 which are integral with and extend `out laterally from the contact members 21 and 23, I do not wish to be limited to this structure. It is obvious that the screws 24 and 27 may be made longer and that the leads thereto may be secured to the contact members themselves, if desired. This is also true or' the screws 13 and 18.

In the modification shown in Figs. 4 and. 5, I provide a generally box-shaped frame which comprises a back wall 46, a pair of side Walls 47 and 48 and a mounting wall 49. The wall 49 is provided with a threaded opening 50 for receiving the threads of a suitable sleeve mounting member. A pair of jack springs 51 and 52 are secured to their respective Walls by means of suitable screws Insulating Washers 54 which lie between the heads of the screws and the springs, serve to properly insulate them from each other. i The springs are in turn insulated from the frame by the insulating Strips55. The springs 51 and 52 are similar to those designated by the numerals 11 and 12, respectively, in Fig. 3 and are also fastened to the frame in the same manner. Suitable spaces are provided between the side walls and the mounting wall to permit mounting of the springs without their touching the frame. To the walls 47 and 48 are' also secured the contact or stop members 56 for the jack springs by means of screws 57. `These are insulated' from the frame 45 by suitable Washers. 58 and the insulating strips 55.

Fig. 6 illustrates the manner in which the springs may be adjusted with respect to the plug when the jack is completely assembled. This is done without loosening the screw which secures the springs to the frame by simply bending the springs into their proper position at the point where they pass through the openings in the frame. In this case one of the springs is shown as being bent from its original dotted line position to the solid line position. In the latter position its contact portion is shown as being in proper engagement with the tip portion of a plug.

Also, in my jack, the effort required to Withdraw a plug therefrom, is greater' than that required to insert a plug therein. The reason for this is shown by referring to Fig. 7 from which it will be obvious that any pull on the plug will cause the spring which contacts with the tip portion thereof to tighten its grip. This result arises from the cramping action of the spring against the plug on account of the angle formed by the ifulcrum and contact portions of the spring with the axis oil the plug. This angle is des ignated by the letter X and is approxi- The result is that in withdrawing a plug from a jack of my inven tion, the pressure exerted on the spring is in the reverse direction with respect to the axis of the spring t'rom that which takes place in the conventional type of jack when the plug is removed. In my jack, a pull on the plug tending to remove it from the jack has a buckling tendency on the spring.

I do not wish to be limited to the details shown or described.

I claim 1. In combination, a jack having a generally U-shaped trame, and jack springs secured to said frame, `said springs being nor* mally in contact with each other adjacent the free ends of the legs of said trame.

2. In combination, a jack frame having a plurality o1 legs and a plurality of jack springs secured to said legs, one of said springs extending in substantially the same direction as said legs and having its free end adjacent the ends of said legs.

SE. In combination, a jack frame having a base portion and a plurality of legs extending away'from said base portion, and a plurality of jack springs secured to each of said legs, each of said springs comprising a relatively long leg and a relatively short leg one oi' said springs oneach leg extending toward the base portion and the other extending away from said portion.

4; In combination, a jack frame having a base portion and a plurality of legs extending away from said base portion, said legs having openings at their ends adjacent the base, and a plurality of jack springs,'said jacl; springs being adapted to extend through said openings for mounting to the legs of said frame.

5. In combination, a jack frame having a plurality of legs, a contact member secured to each leg, and a plurality of jack springs mounted on Said legs and normally in contact with said contact members.

6. In combination, a jack frame having a base portion and a plurality of legs extende ing therefrom, a contact member secured to each leg substantially adjacent its free end, and a jack spring secured to each leg of said frame at substantially its other end, each of said jack springs being adapted to normally remain in contact with said contact member.

'i'. In combination, a jack frame having a plurality oi:l legs, jack springs mounted on said legs, and means fastened to said frame for contacting with said springs and for holding said springs under tension.

8. In combination, a jack frame having a plurality of legs, a plurality of jack springs mounted on said legs, and means adapted to lill? Contact with said springs by holding said springs in tension, said means comprising a plurality ot' contact members having mounting portions and laterally extending p\r tions, said laterally extending portions being adapted to hold said springs.

9. ln combination, a jack trame having a lateral extension, a jack spring having a relatively short leg' and a relatively long leg mountedv on said extension, and a contact member also mounted on said extension, said Contact member being adapted to engage with the long leg of said spring for holding said spring under tension.

l0. In combination, a panel having an opening, a sleeve, extending through the opening` in said panel, a jack traine having a plurality of legs mounted on said sleeve, a plurality of contact members secured to the tree ends ot the legs oi said trame, a plurality ot jack springs mounted on said trame adjacent said sleeve and normally in contact with said contact members, and a plug adapted to extend through said sleeve tor n'ioving` said jack springs out ot Contact with said contact members.

1.1. In combination, a j ack 'frame having` a threaded opening, a jack spring comprising a relatively long leg and a relatively short leg, said short leg having a countersunk opening therein, and means Jfor securing said jack spring to said frame, said means comprising an insulating Washer between the frame and the short leg' of said spring, a second washer having a depressed portion which is adapted to iit into the countersunt: opening in said spring, and a screw having a conical portion below its head which is adapted to fit into the depressed portion in said washer, said screw being adapted to thread into` the threaded opening in said jack trame for holding said jack spring to said frame.

l2. In combination, a jack frame adapted to cooperate with a plug having a plurality of independent openings, a plurality of ack springs extending through said openings, one end of each of said jack springs being secured to said frame, and a plurality of Contact members mounted on said frame, said contact members serving to limit .the movement of the tree ends ot' said springs.

13. In combination, a jack frame oi U- shape, a threaded thimble connected to the bottom of the U, and Contact springs mounted on the sides of the U andhaving their 'tree ends extending in a direction away from the thimble. Y j

le. In combination, a U-shaped frame, springs mounted on'the sides of the frame and having' their outer tree ends disposed/at the outer tree ends ot the frame,and `stops for the outer free ends of .the springs to limit the motion ot said springs toward'each other. f

l5. In combination, a frame having a threaded opening, a metal screw Vhaving a shank threaded into said opening, a Washer ot insulating material about said opening, a metal plate having a hole therethrough of a larger diameter than the shank otr said screw, and a second washer on said screw outside of said'plate, said Vscrew having a conical surface at the upper end of the shank `Afor drawing the inner margin ot said second washer into the opening of theV plate.

ln witness whereof, I hereunto subscribe my name this 8O day of November, 1925. 'f

NEWTON C. SCHELLENGER. 

